Improved synthetic methods for making lactones

A method of making Compound of Formula I (Compound 1) comprising the step of treating a Compound of Formula II (Compound 2) with an oxidizing agent and an acid or base in a suitable solvent (e.g., aqueous solvent):

• wherein the reaction proceeds in a single vessel without the isolation of any intermediates;
• wherein R is H or a protecting group (e.g., an ether, an ester, or a silyl ether protecting group), Ra and Rb are each independently selected from H, optionally substituted C1-6alkyl, or optionally substituted aryl, or wherein Ra and Rb together form a 4-10 membered optionally substituted cycloalkyl ring, and n is an integer from 1 to 5 (e.g., 1, 2 or 3).